1. Field of the Invention
This invention concerns an improved fire extinguishing composition containing bromotrifluoromethane.
2. Description of the Prior Art
The practice of introducing a fire-inert gas into the atmosphere surrounding a fire or a potential fire to extinguish or prevent fire is known. The first gases used in this application, such as carbon dioxide, operate primarily to deny sufficient oxygen to support combustion of the fuel. Other effects of such fire-inert gases are to dilute the flammable vapors and to cool the flammable vapor/air mixture. When sufficient fire-inert gas has been mixed with the atmosphere surrounding the fire site such that the flame is extinguished and new fire is prevented from igniting, the atmosphere is said to be inerted.
Volatile fluorohalocarbons containing bromine, such as CBrF.sub.3, CBrClF.sub.2, CBr.sub.2 F.sub.2, and CF.sub.2 Br-CF.sub.2 Br have now been found strikingly more effective in extinguishing fire than are the older fire-inert gases. Because of the great efficacy of CF.sub.3 Br, it has been postulated that compounds of this class extinguish fire by capturing free-radicals thus terminating flame reactions. Such compounds are called inhibitors to distinguish them from the older fire-inert gases.
In spite of their clear superiority over the older fire-inert gases, the bromine-containing fluorocarbons are only slowly finding a market because of their relatively high cost. There is a need, therefore, for new and more economical methods for using bromotrifluoromethane and similar compounds as fire extinguishants. An effective extinguishant composition containing less of the expensive fluorohalocarbon will be of value, even though limited in the type of fire it will extinguish. The measure for evaluating extinguishants of this type is the volume percent in air of the fluorohalocarbon composition necessary to extinguish the fire.